Imaging of Circulatory Disturbances

Question 1

What are anatomical vascular imaging methods?

Answer 1

• Plain films
• Contrast angiography
• Ultrasound
• CT/MRI

Question 2

What are functional vascular imaging methods?

Answer 2

• Radionuclide imaging
• MRI functional imaging
• Ultrasound

Question 3

What are problems with vascular imaging?

Answer 3

• Soft tissue contrast
• Functional significance of lesions
• Is treatment effective

Question 4

What is the problem with using contrasts?

Answer 4

We can’t see some important structures very well:

• Blood vessels
• Lumen of hollow viscera

Question 5

What are the ideal properties of a man-made contrast agent in radiology?

Answer 5

• Inert: won’t react with body of tissues
• Painless
• Easy to use

Question 6

Features of Iodinated contrasts?

Answer 6

• Differential Xray attentuation
• Inert
• Stable in selected body compartments
• Painless
• Easy to use
• Cheap

Question 7

What are problems with Iodinated contrasts?

Answer 7

• Major reactions
• Renal dysfunction
• Disurbance of thyroid metabolism
• Disturbance of clotting
• Seizures
• Pulmonary oedema

Question 8

Features of Parental Iodinated contrast

Answer 8

• Metallic taste
• Feeling of warmth
• Arterial injections: Micturition, discomfort
• Rarely nausea

Question 9

Metformin and contrast agents

Answer 9

Metformin is a drug used to treat type II diabetes

- This can cross react with contrast agents!

Question 10

Features of catheter angiography

Answer 10

• Vessel punctures and catherised
• Sterile procedure
• Contrast injected using pump injector
• Rapid series of images acquired

Question 11

Interventional Radiology: minimal invasive treatment techniques

Answer 11

• Angiography/Angioplasty
• Embolisation
• Catheter thrombolysis
• Drainage of abscesses
• Nephrostomy
• Vertebroplasty

Question 12

When would you use Angioplasty?

Answer 12

• Short stenoses or occlusions
• Sessile/concentric plaques
• Iliac > sfa > popliteal > crural
• “not as long lasting as surgery but not as dangerous”

Question 13

What else is used apart from Iodine containing contrast agents?

Answer 13

Carbon Dioxide

• A negative contrast agent!
• Useful in patients with poor renal function or sensitivity to iodinated contrast agents.
• CO2 gets absorbed really quickly in vessels.

Question 14

What are problems with Angioplasty?

Answer 14

• Occlusion
• Dissection
• Embolisation
• Rupture
• Infection

Question 15

Features of Ultrasound

Answer 15

• No radiation dose
• Quick
• Non-invasive
• Resolution vs Penetration
• May be physiological
• Operator dependant

Question 16

A man presents with a swollen leg. An ultrasound test confirms a Deep Venous Thrombosis.
What does the ultrasound show?

Answer 16

The vein is distended and non-compressible on gentle pressure of the ultrasound probe

Question 17

Features of normal vein on ultrasound

Answer 17

Normal vein has low pressure and is compressible

DVT - vein is full of thrombus and is not compressible

Question 18

What can Radionuclide imaging be used for?

Answer 18

• Perfusion
• Blood loss
• Perfusion of transplant kidneys
• Blood loss into gastrointestinal tract

Question 19

Features of V/Q (ventilation perfusion scan)

Answer 19

It is useful in the evaluation of pulmonary embolism

Question 20

Features of Nuclear Medicine

Answer 20

• IV injection only
• Good patient compliance
• Radiation dose
• Very insensitive
• Very non-specific
• Easy to arrange

Question 21

Features of Computed Tomography Angiogram

Answer 21

• Gives information about other structures
• Sensitive
• IV injection only
• Radiation dose
• High contrast dose
• Expensive

Question 22

Features of Magnetic Resonance Angiography

Answer 22

• Sensitive
• Specific
• no radiation
• No nephrotoxic contrast
• Very expensive
• Needs state of the art machinery
• High contrast cost